| 摘要 |
PROBLEM TO BE SOLVED: To make a variable tool diameter type main spindle device compact by reducing drive resistance in changing of a tool diameter.SOLUTION: A variable tool diameter type main spindle device includes: an external main spindle 2 supported rotatably in a casing 11; an internal main spindle 3 inserted rotatably and eccentrically with the external main spindle 2; a main spindle motor 12 rotating the internal main spindle 3; an eccentric motor 13 rotating the external main spindle 3 through an external main spindle rotating mechanism 4; and a synchronous rotating mechanism 5 rotating the internal main spindle 3 and external main spindle 2 in one body by transmitting rotation of an internal main spindle drive gear 31 by the main spindle motor 12 to an external main spindle drive gear 21. A tool diameter varying mechanism 8 includes a drive gear 6 which is driven by the main spindle motor 12 and has an internal gear 62 engaged with the internal main spindle drive gear 31, and an internal gear 62 is engaged with the internal main spindle drive gear 31 so as to make the internal main spindle 3 rotate on the axis of rotation of the internal main spindle 3 while revolving around the axis of rotation of the external main spindle 2. |
